engine performance
#41
Drifting
Assuming this is a 4.030 x 3.75 " stroke engine....
The cross section of the head is large. The piston speed, rpm range, and the CID doe not put a lot of demand on the head so the air speed through the intake track is SLOW. To make power you want to maximize port velocity in the rpm range that engine is going to run in. The heads on this build would maximize the head's CSA around 7300 rpm and above.
To help the matter you would put a small camshaft in this to open and shut the valve quick. This would help maintain a better port velocity at the rpm range this engine is going to be driven in.
2nd issue is the 2.100" valve. In a 4.030 bore as the intake valve starts to open it is right up against the cylinder wall. This disrupts airflow and will cause issues in the combustion chamber with the mixing of air and fuel. Since the fuel and air mixture will be disrupted getting the timing right will be like herding cats.
The combination will need to be fixed to get the "butt o meter feel" of acceleration.
The cross section of the head is large. The piston speed, rpm range, and the CID doe not put a lot of demand on the head so the air speed through the intake track is SLOW. To make power you want to maximize port velocity in the rpm range that engine is going to run in. The heads on this build would maximize the head's CSA around 7300 rpm and above.
To help the matter you would put a small camshaft in this to open and shut the valve quick. This would help maintain a better port velocity at the rpm range this engine is going to be driven in.
2nd issue is the 2.100" valve. In a 4.030 bore as the intake valve starts to open it is right up against the cylinder wall. This disrupts airflow and will cause issues in the combustion chamber with the mixing of air and fuel. Since the fuel and air mixture will be disrupted getting the timing right will be like herding cats.
The combination will need to be fixed to get the "butt o meter feel" of acceleration.
#42
Safety Car
The most important flow numbers are NOT MAX numbers, the intake cycle sees that 1 time. Apparently his mid and low lift numbers are good because he states it squats and goes on nitto street radials.
My question is, are we now measuring performance based on tire spinning ?
Or what he clearly states as real world information ?
I see nothing wrong with his car matter of fact my ZZ430 performed exactly as he describes as well as the ZZ465 I upgraded it to. The car would squat and take off like a rabbit.
I bet ya his car does this ..
http://vid1294.photobucket.com/album...psf893deb9.mp4
#43
Instructor
Thread Starter
that pretty close, I have a 2700-3000 stall, does that car have a stall in it? One of the ways I was measuring it, does fell like it is pushing you into the seat?
#44
Safety Car
That was 2400 to 2600 . As far as feeling it seat of paints . I have a SBC 427 with a lot more hp than you see in that video and people who ride with me feel it I dont
Last edited by diehrd; 11-30-2015 at 05:52 PM.
#45
Safety Car
So we know the power comes on way lower then 7300 . And it ends at or before 6000.. The dyno being our only point of reference seams to show respectable power with a reasonably low rpm power band.
The most important flow numbers are NOT MAX numbers, the intake cycle sees that 1 time. Apparently his mid and low lift numbers are good because he states it squats and goes on nitto street radials.
My question is, are we now measuring performance based on tire spinning ?
Or what he clearly states as real world information ?
I see nothing wrong with his car matter of fact my ZZ430 performed exactly as he describes as well as the ZZ465 I upgraded it to. The car would squat and take off like a rabbit.
I bet ya his car does this ..
http://vid1294.photobucket.com/album...psf893deb9.mp4
The most important flow numbers are NOT MAX numbers, the intake cycle sees that 1 time. Apparently his mid and low lift numbers are good because he states it squats and goes on nitto street radials.
My question is, are we now measuring performance based on tire spinning ?
Or what he clearly states as real world information ?
I see nothing wrong with his car matter of fact my ZZ430 performed exactly as he describes as well as the ZZ465 I upgraded it to. The car would squat and take off like a rabbit.
I bet ya his car does this ..
http://vid1294.photobucket.com/album...psf893deb9.mp4
Last edited by bluedawg; 12-01-2015 at 12:42 AM.
#46
Le Mans Master
Member Since: May 2002
Location: Lebanon Township New Jersey
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Spinning tires is not a goal, it is a side effect of power and gearing. Take that thing to a track and really see how it performs instead of trusting your butt meter. Any C3 that just "squats and goes" on the street is a dog.
#47
The track numbers don't lie. Even if you spin off the line your trap speed will still be close. You have 1320 ft to get up to speed.
#48
The other issue is the 210 heads. 195 cc heads are probably a better choice for that motor. And the cam specs need revisiting as well. But like he has said, start with the converter and go from there.
#49
I agree with that. Track numbers are something I can relate to. They don't lie. Dyno numbers are just that...numbers....just use them for tuning thats it.